<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <script>
        // 1.绝对值
        console.log(Math.abs(1)); //1
        console.log(Math.abs(-1)); //1
        console.log(Math.abs('-1')); //隐式转化
        console.log(Math.abs('pink')); //NAN
        // 2.三个取整方法
        // （1）Math.floor() 向下取整
        console.log(Math.floor(1.1)); //1
        console.log(Math.floor(1.9)); //1
        // （2）Math.ceil() 向上取整
        console.log(Math.ceil(1.1));
        console.log(Math.ceil(1.9));
        // （3）Math.round() 四舍五入
        console.log(Math.round(1.4));
        console.log(Math.round(1.9));
        console.log(Math.round(-1.5)); //.5特殊 它往大了取 所以-1.5 取-1
    </script>
</head>

<body>

</body>

</html>